Lipid metabolism and antioxidant system contributed to salt salinity tolerance induced by Na+ accumulation in halophytic grass seashore paspalum

Abstract Background and aims Soil salinization is a growing problem for agriculture worldwide. To elucidate the mechanism underlying the salt tolerance of halophytes can offer a new angle for developing salt−tolerant crops. Seashore paspalum (Paspalum vaginatum Sw.) is a halophytic turfgrass and genomic model system for salt tolerance research in cereals and other grasses. However, knowledge regarding the tolerance mechanism of this halophyte remains largely unknown. Methods The two P.vaginatum accessions with contrasting salinity tolerance were employed to investigate the relationship between Na+ accumulation, lipid metabolism, antioxidant response and tissue−dependent salt tolerance using ICP−MS−based ion analysis, lipidomic profiling analysis, enzyme assay and integrated transcriptomic and metabolomic analysis, respectively. Gene−metabolite network analysis was carried to identify the significant TF genes and metabolites associated with salt tolerance in P.vaginatum plants. Results We found that salt−tolerant P.vaginatum built up tissue−specific strategies accompanied with Na+ accumulation in response to salt stress. Antioxidant system and amino acid metabolism were curial to maintain high salinity tolerance in leaves of P. vaginatum plants. On the contrary, lipid upregulation is the important components of the salt−tolerant mechanism in roots of P. vaginatum. Furthermore, 109 TF genes were identified to be linked to salt tolerance, conferring to salinity tolerance in this halophytic grass. Conclusions Our results expand our understanding of the underlying salt tolerance of seashore halophyte grass for the breeding and genetic engineering of salt tolerance in crop plants.